I think the current thinking about creams and bioequivalency usually involvesdemonstrating and equivalent effect as opposed to an equivalent amount ofdrug absorption at the treatment site on the skin. However, there was aproposal by a gentleman at the FDA to use dermal drug concentrationmeasurements, measured by tape stripping and analyzed using"dermatopharmacokinetics" to establish bioequivalency. There was documentavailable on the FDA website discussing this and paper in an AAPS publicationin 1997 that discussed this also.